PURIFICATION OF OILY WASTE-WATER BY ULTRAFILTRATION

Investigations have been carried out for purification of oily wastewat er by a combination of ultrafiltration/reverse osmosis processes. A tu bular ultrafiltration system using cellulosic and non-cellulosic membr anes was tested with typical oily wastewater collected from harbour an d simulated emulsion without any pretreatment. Both membrane types pro duced a permeate with an oil content generally less than 10 mg/dm(3). Rejection of chemical oxygen demand (COD) is 80% for ultrafiltration t reatment. The permeate is generally of acceptable quality for direct s ewer discharge. For further treatment of UF permeate, reverse osmosis was applied with tubular B1 PCI modules using cellulose acetate membra nes. The rejection of COD after ultrafiltration/reverse osmosis treatm ent increased up to 98.5% and total dissolved solids (TDS) to 95.7%. R everse osmosis treatment will permit reuse of the treated water as pro cess water.